1. Field of the Invention
The present invention relates to systems and methods for protecting vehicle occupants from injury. More specifically, the present invention relates to covers that permit multi-axis deployment of inflatable cushions.
2. Technical Background
The inclusion of inflatable safety restraint devices, or airbags, is now a legal requirement for many new vehicles. Airbags are typically installed in the steering wheel and in the dashboard on the passenger side of a car. Additionally, airbags may be installed to inflate beside the passenger to provide side impact protection, in front of the knees to protect the knees from impact, or at other strategic locations.
In the event of an accident, an accelerometer within the vehicle measures the abnormal deceleration and triggers the ignition of an explosive charge. Expanding gases from the charge fill the airbags, which immediately inflate to protect the driver and/or passengers from impact against the interior surfaces of the vehicle. During normal vehicle operation, airbags are typically stowed behind covers to protect them from tampering and provide a more attractive interior facade for the vehicle.
Unfortunately, vehicle occupants may move considerably from optimal impact positions. For example, a passenger may be adjusting the radio or air conditioning settings, tending to a child in the rear seat, reclining in the seat, or otherwise moving in a manner that positions part of their body outside the protection zone of a conventional airbag. Hence, when impact occurs, a part of the person""s body may strike the vehicle interior outside the perimeter of the airbag, or the person may even be injured in some manner by the inflating airbag. Also, occupants that are small, such as children, may move outside the protected area of a conventional airbag in a collision.
This shortcoming is caused, at least in part, by the fact that many known airbags inflate only in a single direction, which is often toward the person. For example, front impact airbags typically inflate primarily in a rearward direction, directly toward the driver or passenger. Hence, interior surfaces of the vehicle that surround the airbag when it is in a stowed position may not be sufficiently covered by the airbag by the time the person""s body moves toward them. Thus, such surfaces are exposed to receive impact with parts of the person""s body that are not aligned with the inflating cushion.
Furthermore, the momentum of the deploying cushion can also be a source of injury to vehicle occupants. When the majority of the gas produced is directed toward the occupant, the mass of the gas will create significant momentum in the deploying cushion. The momentum of the bag toward the person has an additive effect on the momentum of the person toward the bag, potentially making the impact more dramatic.
The deployment of known cushions or curtains is often determined, at least in part, by the configuration of the covers that contain them. Many known covers have seams arranged to permit emergence of the cushion in essentially a single direction. Lateral or transverse deployment of the cushion is restricted by walls of the cover.
Accordingly, a need exists for airbag covers that permit deployment of a folded cushion along multiple directions. Such covers are needed for a wide variety of airbag types, including driver""s side airbags, passenger""s side airbags, side impact airbags or xe2x80x9cinflatable curtains,xe2x80x9d and knee airbags. Multi-axis deployment should preferably occur in normal operation of the cover, and not simply in the event that deployment toward the person is obstructed. Furthermore, such a cover should preferably be easily manufactured and installed in a vehicle.
The apparatus of the present invention has been developed in response to the present state of the art, and in particular, in response to problems and needs in the art that have not yet been fully solved by currently available airbag systems. Thus, it is an overall objective of the present invention to provide airbag covers that permit consistent multi-axis deployment. These covers provide enhanced protection for vehicle occupants that are outside their nominal positions when impact occurs without unduly adding to the momentum of the person""s impact with the cushion.
In a first embodiment of the present invention, the cover has a generally pentagonal shape. However, the cover could be formed in other shapes such as an elongated rectangle or a rounded disk. A folded cushion is disposed within the cover.
The cover has a frontal direction generally directed toward a protected occupant of a vehicle in which the cover is placed. The cover also includes one or more lateral directions that are generally perpendicular to the frontal direction. The cover further includes semi-lateral directions that are generally directed between the frontal direction and the lateral directions.
The cover includes an attachment portion designed to be attached to the interior of the vehicle or housing, and a deployment portion that opens to permit emergence of the folded cushion. The deployment portion includes a frontal region and a peripheral skirt. The frontal region is divided into a plurality of frontal portions by frontal frangible seams. In response to expansion of the cushion, the frontal frangible seams break to permit the frontal portions to separate from each other so that the cushion can deploy in a frontal direction.
In this embodiment, the frontal frangible seams are formed in a T-shaped configuration to define a first, second, and third frontal portion. The first frontal portion has a generally rectangular in shape, while the second and third portions have a generally trapezoidal shape. The T-shaped seam configuration can be oriented in various directions and positioned at various locations on the frontal region. Alternatively, the frontal seams may be formed in other configurations that define three or more frontal portions, such as a Y-shaped configuration.
The deployment portion also includes a junction between the frontal region and the peripheral skirt. The frontal region and the peripheral skirt meet at approximately a right angle. However, the junction can include rounded or angled transitions from the frontal region to the peripheral skirt. The junction is comprised of junction seams, hinged junctions, and/or fixed junctions. The junction seams break in response to expansion of the cushion to permit the frontal portion to separate from the peripheral skirt. Separation of the frontal portion from the peripheral skirt permits the cushion to emerge in one or more semi-lateral directions. The hinged junctions allow an attached frontal portion to rotate with respect to the peripheral skirt. The fixed junctions maintain a generally fixed relationship between an attached frontal portion and the peripheral skirt during expansion of the cushion. As will be understood by those skilled in the art, the position and size of the junction seams, hinged junctions, and fixed junctions may be varied within the scope of this invention.
In certain implementations of the cover, the peripheral skirt is divided into a plurality of skirt portions by skirt seams. The skirt seams break in response to expansion of the cushion to permit the skirt portions to separate from each other. Separation of the skirt portions from each other permits the cushion to emerge from the cover in one or more lateral directions. Also, skirt hinges permit rotation of the skirt portions relative to adjacent parts of the peripheral skirt. The position and size of the skirt hinges and seams may be varied within the scope of this invention.
The cover includes a boundary between the attachment portion and the peripheral skirt. The boundary is comprised of fixed boundaries, boundary seams, and/or hinged boundaries. A fixed boundary maintains a generally fixed relationship between the attachment portion and an attached part of the peripheral skirt during expansion of the cushion. The boundary seams break in response to expansion of the cushion to permit separation of the attachment portion from the peripheral skirt so that the cushion can deploy in a lateral direction. The hinged boundaries allow portions of the peripheral skirt to rotate with respect to the attachment portion during expansion of the cushion. By varying the position and size of the fixed boundaries, boundary seams, and/or hinged boundaries the first embodiment may be made in a number of different ways.
A second embodiment of the cover has a generally square or rectangular shape. As in the first embodiment, the frontal frangible seams are formed in a T-shaped configuration to define three frontal portions. Each of the frontal portions is generally square or rectangular in shape. The frontal frangible seams break to enable emergence of the cushion in a frontal direction. As in the first embodiment, the T-shaped seam configuration can be oriented in various directions and positioned at various locations on a frontal region within the scope of this invention.
As in the first embodiment, junction seams may be positioned at various locations to enable deployment of a covered cushion in one or more semi-lateral directions. Also, the position and size of skirt seams and boundary seams can be varied to provide for deployment of the cushion in one or more lateral directions.
A third embodiment of the cover has a generally square or rectangular shape. Unlike previous embodiments, the frontal frangible seams are formed in an I-shaped configuration to define four frontal portions. The frontal frangible seams break to enable emergence of the cushion in a frontal direction. Each of the frontal portions is generally rectangular or square in shape. The I-shaped seam configuration may be oriented in various directions on the frontal region. Alternatively, the frontal seams can be formed in other configurations that define four or more frontal portions. As in the first and second embodiments, the junction seams, skirt seams, and/or boundary seams can be positioned in various locations to enable deployment of the cushion in one or more semi-lateral and/or lateral directions.
In view of the foregoing, through the use of the covers of the present invention, vehicle occupants may be more fully protected against injury. Occupants who are out of their nominal positions may obtain greater protection from cushions that inflate laterally and transversely as well as toward them. Additionally, multi-axis inflation may relieve a portion of the momentum imparted to the person by the airbag, thereby decreasing the possibility of injury due to impact with the airbag cushion.
These and other objects, features, and advantages of the present invention will become more fully apparent from the following description and appended claims, or may be learned by the practice of the invention as set forth hereinafter.